1. Field of the Invention
The present invention relates to a torque control device, and more particularly to a torque control device for electrical tools, where the control device can automatically interrupt a power supply of the electrical tools if a detected actual torque is greater than a default torque value.
2. Description of Related Art
Electrical tools commonly have an electrical motor to drive a tool head thus assisting an operator to easily accomplish operations such as screwing or drilling. Each kind of tool head can sustain a particular torque corresponding to a target object to be driven. Therefore, the torque generated by the electrical tools is required to be adjustable for accommodating different target objects. If the torque exceeds a tolerable range that the tool head can sustain, this tool head will be temporarily disengaged from the motor so as to avoid possible damage to the tool head and the motor.
The default torque setting can be accomplished by mechanically varying the compressing extent of a spring installed in the electrical tools. The tool head is driven by the motor as long as the torque is within the default value. However, using the spring to mechanically set the torque and obtaining a precise default value are both very difficult. Further, even when the tool head has been temporarily disengaged under the motor, the motor in the idling status continuously consumes power.
Therefore, the invention provides a torque control device for electrical tools to mitigate or obviate the aforementioned problem.